黑云母 hēiyúnmǔ biotite Definitions Defs Origin Strokes Stroke Words Sentences Sents 黑 hēi adjective black the color of coal or ink; opposite of 白 bái云母 雲母 yúnmǔ mica A type of mineral mainly composed of silicates that comes in various colors and can be split into thin, flexible, transparent sheets; it is highly resistant to heat and electricity, making it an important insulating material.
